x86-32: use specific __vmalloc_start_set flag in __virt_addr_valid

Rather than relying on the ever-unreliable system_state,
add a specific __vmalloc_start_set flag to indicate whether
the vmalloc area has meaningful boundaries yet, and use that
in x86-32's __phys_addr and __virt_addr_valid.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 433f7bd..a23ca5b 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -76,10 +76,9 @@
 #ifdef CONFIG_DEBUG_VIRTUAL
 unsigned long __phys_addr(unsigned long x)
 {
-	/* VMALLOC_* aren't constants; not available at the boot time */
+	/* VMALLOC_* aren't constants  */
 	VIRTUAL_BUG_ON(x < PAGE_OFFSET);
-	VIRTUAL_BUG_ON(system_state != SYSTEM_BOOTING &&
-		is_vmalloc_addr((void *) x));
+	VIRTUAL_BUG_ON(__vmalloc_start_set && is_vmalloc_addr((void *) x));
 	return x - PAGE_OFFSET;
 }
 EXPORT_SYMBOL(__phys_addr);
@@ -89,7 +88,7 @@
 {
 	if (x < PAGE_OFFSET)
 		return false;
-	if (system_state != SYSTEM_BOOTING && is_vmalloc_addr((void *) x))
+	if (__vmalloc_start_set && is_vmalloc_addr((void *) x))
 		return false;
 	return pfn_valid((x - PAGE_OFFSET) >> PAGE_SHIFT);
 }